Four-terminal Guarded Coaxial Scanner

Announcement Type: Special Notice

Classification Code: 6695

Announcement Number: NB684050-25-01320

Subject: Notice of Intent to Noncompetitively Acquire Four-terminal Guarded Coaxial Scanner

The National Institute of Standards and Technology (NIST), Physical Measurements Laboratory (PML), Fundamental Electrical Measurement (FEM) group realizes and maintains the units of resistance, capacitance, and inductance for the United States. To support and verify the automated connection of resistance standards at dc requires guarded coaxial switching of four-terminal standards, including the shields of the connections.

This notice is not a request for a quotation. A solicitation document will not be issued and quotations will not be requested.

This acquisition is being conducted under the authority of FAR 13.106-1(b) via FAR 13.106-1(b). The North American Industry Classification System (NAICS) code for this acquisition is 334516, Analytical Laboratory Instrument Manufacturing.

In order to meet the mission indicated above, FEM requires instruments to automate the connection of four-terminal electrical resistance standards to measurement systems such as resistance bridges and cryogenic current comparators. Measurements will be made using artifact standards and graphene quantum Hall array resistance standards (QHARS) with low uncertainty traceable to fundamental constants. Guarded coaxial connections provide a solution to electrical/thermal noise errors associated with leakage currents to ground that can effect high accuracy electrical measurements at parts in 10-7 to 10-8 uncertainty level.

1. Minimum Requirements

The system shall meet or exceed the minimum requirements identified below. All items must be new. Used or remanufactured equipment will not be considered for award. Experimental, prototype, or custom items will not be considered. The use of “gray market” components not authorized for sale in the U.S. by the Contractor is not acceptable. All line items shall be shipped in the original manufacturer’s packaging and include all original documentation and software, when applicable.

Contract Line Item Number (CLIN) 0001: The Contractor shall provide four (4) four-terminal Guarded Scanners that meet the following minimum requirements:

1. Electro-mechanically connect four-wire input signal pairs (High and Low), where each pair has 2 insulated center conductors and a shield to one of 10 to 16 output channels (High and Low), where each pair has 2 insulated center conductors and a shield. The scanner must provide for the connection of four-terminal guarded standard resistor to four-terminal guarded resistance bridges is needed, where the center conductors and associated shields which are connected with the selection of a channel. Each channel has a pair of High and Low set of leads, with separate and isolated shields switched. High and Low shields must be isolated from each other. The guarded shields surround the pairs of conductors and can be driven at a guard potential, up to 1000 volts.


2. Shall be remotely programmable through IEEE-488 (GPIB) interface as well as operated from front panel.


3. Shall have guarded coaxial connections for input and output terminals with all shields isolated from the instrument chassis and other input/output shields, allowing the shields to be driven at guard potential.


4. Guarded cable lengths shall not exceed six (6) feet. One (1) pair of input cables, sixteen (16) pairs of output cables. Each cable has 2 conductor stranded copper with Polyethylene (PE) insulation, surrounded by braided guard shield with insulation outside. Alternatively, termination of guarded cables may be on the back panel using pairs of coaxial connectors (BNC, N-type, or BPO) for each cable with all connector shields isolated from the instrument chassis and each other. The pairs of connectors shields must be connected only to the shield of the input/output cable.


5. Contact life greater than 10,000,000 cycles.


6. Leakage resistance greater than 1 x 1012 Ω without the guard circuit energized.


7. Shall include hardware for mounting in nineteen (19) inch instrument rack.

NIST conducted market research from October 2024 to April 2025 by internet searches, discussions with sources, and a sources sought posting. Sources sought NIST-SS25-26 was posted from March 28, 2025 to April 11, 2025. No responses were received. The results of that market research revealed that only Data Proof, LLC, 3911 Hazy Swale Way, Sparks, NV 89436, United States UEI: LYNXRK6NLPM1 appears to be capable of meeting NIST’s requirements. However, any sources that believe they are capable of meeting NIST’s minimum requirements are encouraged to respond to this notice by the response date to provide the following information at a minimum: Company Unique Entity Identifier number in https://sam.gov; details about what your company is capable of providing that meets or exceeds NIST’s minimum requirements; whether your company is an authorized reseller of the product or service being cited and evidence of such authorization; and any other information that can help NIST determine whether this requirement may be competitively satisfied.